Adolphus john lustig



( No Model.)

A. J. LUSTIG.

PROCESS OP MANUFACTURING GOMPOND 4METAL PLATES 0F @i Patented Nov'. 9,1886.

N. PErins. mmullwghprmr, wnhngwn. D. C.

NITED STATES PATENT OFFICE.

ADOLPHUS JOHN LUSTIG, OF NEW YORK, N. Y., ASSIGNOR OF ONE-FIFTH TO LOUISKAHN, OF SAME PLACE.

PROCESS OF MANUFACTURING COMPOUND METAL PLATES F PRECIOUS METALS.

SPECIPICA'JIONforming part of Letters Patent No. 352,475, dated November9, 1886.

Application filed March 23, 1886. Serial No. 196,212.

To all whom it may concern.-

Be it known that I, ADoLPHUs J oHN LUs- TIG, of the city of New York, inthe county and State of New York, have invented a new and ImprovedProcess of Manufacturing Compound Metal Plates outv of Precious Metals,of which the following specification is a full, clear, and exactdescription.

This invention relates to an improved pro- Io cess of manufacturingcompound metal plates out of precious metals.

The invention has reference more particularly to the processes in whichone stratum of molten metal is cast against one stratum ofsolidhighly-heated metal; andit consistsin the elements of improvementhereinafter more fully pointed out. v Y

The accompanying drawings illustrate an apparatus for carrying myprocess into effect. In the drawings, Figure l is a perspective view ofthe mold. Fig. 2 is an upright section online :v x, Fig. l; Fig. 3, ahorizontal section on line y y, Fig. l. Fig. 4 is a horizontal sectionof the furnace, with the mold therein shown in plan. Fig. 5 isa sectionthrough the product.

I propose to use the following-described method of uniting either twograded metals, one graded and one ungraded, such as gold and 3o silver,gold and composition, silver and copper, and, lastly, one stratum ofgold, one of silver, and one of gold.

The plate a, of the higher grade of gold or silver that is to becompounded, is made of a 3 5 breadth somewhat smaller than the recessprovided for it in the receiving-mold A, in order to allow room forexpansion at its sides, as shown at c, Fig. 3. The plate a is made highenough to allow for expansion and the adjustment of a guard-bar, Z), onthe top of the plate, so as to prevent any inflowing metal to flow uponthe plate and cut it out. The plate a is straightened out so as to beperfectly true, and so as to rest on all its parts on a wroughtironplate, d, that holds a stratum of asbestus, e, in place, the asbestuswithin the ingot-mold being for the purpose of throwing the heat of theinflowing metal upon the plate a to be compounded. After having madesure of the 5o perfect level of the plate, the same is rubbed (Nomodi-l.)

on its free side with sand-paper, for the purpose, first, of preparing aroughened holding-ground for theliquid metal, and, secondly,

of ridding the surface of the plate of all oxidized metal. Upon thisroughened surface dried borax rubbed in water is put, and the wholesubjected to a sufficient heat to melt the borax in such a way that thewhole surface of the plate presents a glazed surface. Should there beany spots left where there is no borax, 6o the operation should berepeated.

Another Way to prepare the gold plate, which as a commercial platecontains copper, would be to subject the plate, after roughening withsand-paper, to sufficient heat to oxidize the copper contained on thesurface, and then plunge the plate into diluted sulphuric acid, andrepeat these operations until there is no copper in the surface. Thetraces of sulphate of copper are then neutralized with cya- 7C nide ofpotassium, and after a final rinsing with hot water pure olive-oil ispoured upon this prepared surface and the same desiccated.

Instead of using animal oil for coating the mold, I may use puregraphite to cover the bottom and sides of the exposed part of the moldA, for the following purposes: to stop the pores of the cast-iron, toprevent friction, to .deo'xidize those parts of the metals poured intothe mold that have become oxidized, and also to prevent radiation. Theprepared plate a is then put into the mold in an upright position, Fig.2, and the guard-bar bis put upon the top of the plate. The mold isputinto a furnace, B, and heated to 1,5000 Fahrenheit. In the meantime themetal to be compounded with the plate is molten, and is then poured,preferably in two streams, into the mold, while the same is still in thefurnace, against the exposed and prepared surface of plate a. 9o

It is well known that fourteen-karat gold melts at 1,925", whileeightkarat melts at 1,6000, but must be brought to about 2,500O to pourwell. A unionwill be effected when the gold plate is brought to 1,8000Fahrenheit by the heat of the molten metal poured into the mold, andstill sufficient heat left in the liquid metal to keep it perfectlyliquid at least fifteen seconds, so as to be able to enter into thepores of the 'solid plate, out of which the air has been loo 2o on whilethe inoldbis in the furnace.

forced, either previously toputting :itinto the mold by melting theboi-ax on it-and leaving it on or by the heat of the furnace. It isevident that the quantity of the liquid metal in 5 relation to the platea to be compounded and the bulk of the mold is of importance, because itis prudent to stop the active heat of the furnace previous to pouring,and consequently a large percentage of heat is lost ro throughradiation, partly of the inilowing metal, as also through radiation atthe sides of the mold, though this latter radiation is partlycounteracted by the asbestus lining of the mold.

As it is of importance to prevent the descent of cold airinto themoldchamber, and thereby \coolthe plate and oXidize not only the fallingmetal, butalso the top ofthe metal within the mold, I provide a cover,f, which is to be put This coyer is to remain in place while pouring.

The furnace should be constructed in such a Way as to be able to heatthe mold not only on the bottom and from the bottom, but the operbottomand increase the samein the middle of thetop of that part of the moldagainst which theplate rests.

"A furnace construct-ed for this purpose is shown in Fig. 4, Where Brepresents a section of the furnace, with openings B B to pass the metalto be cast into the mold A. These openings are provided with suitabledoors to close the same when required, and the top of the furnaceconsists of a movable cover to lallow the mold to be inserted'orremoved.

B2 B3 B4 are branches of gaspipes arranged at different heights to beable to direct the gasfianie to any part of the back 4,of the mold itmay be found desirable.

I claim as 'niy invention- The process of producing compound metalplates, which consists in roughening one plate, oxidizing it, placing itin diluted sulphurc acid, pouring oil uponit, placing itinto a mold, andpouring liquid metal upon and alongside of it while the mold :is heated,substantially as speci tied.

ADOLPHUS Witnesses:

Louis KAHN, Mosns KAHN.

JOHN LUSTIG.

